Magnetic contactor



H. E. WHITE MAGNETI C CONTACTOR Filed March 24, 1928 I5 Sheets-Sheet 1INVENTOR Harold E, Wh/fe TORNEY June 0, 1930. H. E. WHITE 1,763,116

MAGNETIC CONTAGTOR Filed March 24, 1928 3 Sheets-Sheet 2 INVENTOR Hare/0E Whife ATT'oRNEY June 10, 1930. H. E. WHITE 1,763,116

MAGNETIC CONTACTOR Filed March 24, 1928 3 Sheets-Sheet 3 1 INVENTORHora/d E, Wh/fe BY. z 7 ATTORNEY Patented June 10, 1930 UNITED STATESPATENT OFFICE HAROLD E. WHITE, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TOWESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OFPENNSYLVANIA MAGNETIC CONTACTOR Application filed March 24, 1928. SerialNo. 264,357.

My invention relates generally to switching devices and particularly toelectro-magnetically operated switches.

In the design of switching devices for maritime service,it is necessaryto employ a means unaffected by rolling and pitching of the vessel, orby the shock of battle, for retaining a switch in its open position.

It is further necessary, on account of the limited space andventilation, that switches used on shipboard be operated at relativelylow temperatures. Therefore, such switches should have all necessaryheat generating elements arranged so that effective ventilation may beeasily accomplished. Switches of this type are equally applicable torailway work where they are subjected to vibration or enclosed in boxesdiflicult to ventilate.

The object of my invention is to provide a 20 magnetically operatedswitch which will be suitable for marine purposes as well as for variousother applications.

A further object of my invention is to provide for retaining anelectro-magnetically operated switch open independently of the force ofgravity.

Another object of my invention is to provide an electro-magneticallyoperated switch whose operating coil and other current carrying elementsare designed to produce minimum heat under load and operate at a lowtemperature.

A morespecific object of my invention is to provide a method of removingthe blow-out coil of a switch from the path of the main current whilethe switch is seated in its closed position, and provide for connectingthe blowout coil in the main circuit during the opening operation of theswitch and before the contact members have separated.

Other objects of the invention will become apparent to those skilled inthe art as the description proceeds.

For a complete understanding of the structure of the invention and theoperation of its parts, reference may be had to the followingdescription which should be read in conjunc tion with the accompanyingdrawings, in which Figure 1 is a view in side elevation of amagnetically-operated switch constructed in accordance with my inventionand shown in its open position,

Fig. 2 is a view in longitudinal section of a magnetically-operatedswitch constructed in accordance with my invention and shown with itscontact members in their closed positions,

Fig. 3 is a view in section, of the switch taken along the line III-IIIin Fig. 2, and

Fig. 4 is a View in end elevation of the switch, as shown in Fig. 2 andillustrating the construction of the interlock contact members.

Referring now to Figs. 1 and 2, the frame member 10 is mounted on aninsulating base 11 to serve as a support for the operating coil 12, thearmature member 13 and the magnetic blow-out device 14. The frame member10 also constitutes a path for the lines of magnetic force establishedupon the energization of the operating coil 12.

The operating coil 12 comprises a number of turns of wire wound about acore 15 and mounted on the frame member 10 by means of the screw 16. Theoperating coil 12 may be energized from any suitable source of powersupply and when energized, a flux is set up which follows a path throughthe core 15, the mounting screw 16, the frame member 10, and thearmature 13 so that the armature attracted to and retained in its closedposition. as shown in Fig. 2.

The armature n'lembcr 13 is pivotally mounted on the frame 10 by meansof the pin 17. The armature 13 is free to oscillate on the pin 17. itsmovement being limited by the core 15 of the coil 12 and the stop 18. Onone end of the armature member 13. a seat 19 is provided and disposed toengage the core 15 when the coil 12 is energized so that a magnetic fluxis established through the coii 1i? and armature member 13. The end ofthe armature member 13 opposite the seat 19 is bifurcated to receive thecontact-carrying member 20. As shown the contact-carrying member 20 ispivotally mounted between the prongs of the armature 13 and is free tooscillate about pin 21. The contact-carrying member 20 is provided witha tail piece to which is attached a tension spring 2 that continuouslybiases it counterclockwise about the pin 21. The counterclockwisemovement of the contact carrier 20 about its pivot pin 21 is limited bythe engagement of the tail piece with the pin 1?. which supports thearmature 13, and the clockwise movement is limited by the engagement ofthe brush 23 with the contact block 24.

One end of the tension spring is attached to the frame member 10 throughthe pin 25 and, as stated above, the other end is attached to the tailpiece oI the contact carrying member 20. When the coil 12 is deenergizedand the armature 13 released, the armature member 13 is retained in itsopen position by the tension spring 22 acting through the contactcarrier 20. A further function oi the tension spring 22 is to provide anincreased contactpressure between the contact members 26 and 27 when thearmature 13 is in its closed position, as shown in Fig. 2.

The stationary contact member 26 is mounted on an insulating base 28 andis disposed to receive the movable contact member 27 which is attachedby screw 29 to the contact-carrying member 20 and actuated by thearmature member 1 and the operating coil 12.

When the operating coil 12 becomes energized, a magnetic flux is set upwhich attracts the armature member 13 and the seat 19 is retained inengagement with the core 15. During the closing operation of thearmature member 18, the contact members 26 and 27 first engage eachother at the curved surfaces near their tips and as the closingoperation continues, the contact member 27 is rotated about the axis 21on which the contact carrying member 20 is pivoted so that when theclosing operation is coinoletmh the flat portions of the contact members26 and 27 are engaged as shown in Fig. 2. During the closing operation.the first engagen'ient of the contact members 26 and 27 occurs near thetips and the contact members roll upon one another as they approachtheir final positions. There is a change of contact surface during theclosing operation and the surfaces which conduct the currentcontinuously through the switch jaws are never afifected by the arcswhich are drawn upon opening and closing the contact members. Therolling and wiping action of the contact members upon one another occurssimilarly during the opening operation of the contact members and thearcs which are drawn and broken at the tips of the contact members 26and 27 can never injure or burn the surfaces through which the currentis continuously conducted when the switch is in its fully closedposition.

A magnetic blow-out device 14 is provided on the switch and comprises acoil 30, a pair of magnetic plates or polepieces 31 which are disposedto concentrai'c the HUB; set up by the coil 80 and produce a magneticfield within the are chute which functions to project arcs drawn ontothe wedge-shaped splitter 3 iVhen an arc is drawn at the tips of thecontact members 26 and 27 and subjected to the influence of the magneticfield within the arc chute, it is stretched and broken about thewedge-shaped arc splitter The blow-out coil 30 is connected to thecontact members through the conductor 34. which is attached to thecontact-carrying member 20 through the screw 35. An extension 2-37 ofthe copper strap which comprises the blowout coil 30 is connectedthrough the screw 38 to the contact block 24 and the blow-out coil isconnected in circuit between the brush 2 and the contact block 24. \Vhenthe switch has completed its closing operation and is in its fullyclosed position so that the brush 23 is in engagement with the contactblock 24, the brush 23 shunts the blow-out coil 30 and no currenttraverses the blow-out coil. In this manner, the heating of a switchhaving magnetic blow-out devices is reduced to a minimum and the heatingCt used by the energization of the coil occurs only during the closingand opening operations of the switch.

Upon the initial engagement of the contact members 26 and 27, thecircuit established through the switch may be traced from the terminal39 through the contact member 26, contact member 27, the contactcarrying member 20, screw 35, conductor 34, blow-out coil 30, conductor37, screw 38, contact block 24 to the terminal 40. As the contactmembers 26 and 27 roll into their fully closed positions, the circuit ischanged and may be traced from the contact-carrying member 20, throughthe brush 23 to the contact block 24 and this circuit is maintained aslong as the switch is entirely closed.

An interlocking device is mounted upon the armature 13 on the endopposite the contact member 27 and this interlocking device comprises aconductor bar 41 insulated from the armature member 13 by the tube 42and actuated by the armature to make contact with either of two sets ofinterlocking fingers 43 and 44. The sets of contact fingers 43 and 44each comprise two lingers and each set is disposed to engage theopposite ends of the conductor bar 41 so that a circuit will becompleted between the individual members of the set of interlockingfingers. From the drawing, it will be seen that the; set of inter--locking fingers 4. 3 is engaged by the conductor bar 41 when the contactmembers are in their open position and the set 44 is engaged by theconducting bar 41 when the armature is in its closed position.

From Figs. 2 and 4. the construction of the mounting structure of theinterlock fingers may be readily understood. Each of the interlockfingers is mounted upon a supporting member as 45 which in turn is;mounted upoii Ill the insulating base member 46. The contacting portionof the interlock fingers is com posed of a metal strip 47 bent into theshape shown in Figs. 1, 2 and 4 and resiliently mounted upon thesupporting member 45. A coil spring 48 is mounted on a pin 49 whichengages the interlocked contact member 47 and the support 46 so thatthrough the action of the spring a resilient mounting of the interlockcontact member is obtained.

Since it will be possible to modify the embodiment of my inventionhereinbefore set forth and adapt it to a number of applications withoutdeparting from the spirit and scope of the invention, it is desired thatthe foregoing description be construed as entirely illustrative and notin a limiting sense.

I claim as my invention:

1. In a magnetically operated switching device, the combination of apivotally mounted armature member, a contact carrying member pivotallymounted on the armature, a movable contact member mounted on the contactcarrying member, a stationary contact member disposed to be engaged bythe movable contact member, a tension spring attached to the contactcarrying member and disposed to bias the armature to its open positionand rotate the contact carry ing member about its pivot point, ablow-out coil disposed to be energized by the current traversing thecont-act members, a contact brush mounted on the contact-carryingmember, a stationary contact block disposed to be engaged by the brushin response to the rotation of the contact carryin member, said brushand contact block being disposed to short-circuit the blow-out coilsubsequent to the engagement of the contact members, and a magnetizingcoil disposed to actuate the arnm ture.

In a magnetically operated switch, the combination of a centrallypivoted armature member, a stationary contact member, a movable contactmember, a contact-carrying men'iber pivotally mounted on one end of thearmature for arrying the movable contact member, said contact-carryingmember being provided with a tail piece, means cooperative with the tailpiece to limit the movement of the contact-carrying member about itspivot point, a tension spring attached to the tail piece of the contactcarrying member, said tension spring being disposed to bias the armaturetowards its open position and to permit the movable contact member torotate into engagement with the station- :2 ry contact member, ablow-out coil disposed to be energized by the current traversing theswitch, a brush mounted on the contact-carrying member, a stationarycontact block disposed to be engaged by the brush when the contactmembers are in their closed position, said brush and contact block beingdisposed to short-circuit the blow-out coil when in engagement, and anexternally mounted magnet coil for actuating the armature.

3. In a magnetically operated switch, in combination, a movably mountedarmature member, a stationary contact member, a movable contact memberpivotally mounted on the armature for engaging the stationary contactmember to establish a circuit, means disposed to permit rotation of themovable contact member on the armature, a blow-out coil for developingan arc-rupturing field about the contact members, said blow-out coilbeing connected in series circuit relation with the contact members, andmeans carried by the movable contact member for establishing a circuitto shunt the blow-out coil in response to the rotation of the movablecontact memher when the contact members are in engagement, and amagnetic coil for actuating the armature.

4. In a magnetically operated switch, in combination, a movably mountedarmature member, a stationary contact member, a movable contact memberfor engaging the stationary contact member to establish a circuit acarrier for the movable contact member pivotally mounted on thearmature, a blowout coil for developing an arc-rupturing field about thecontact members, said blow-out coil being connected in series circuitrelation with the contact members, an auxiliary contact member carriedby and electrically connected to the movable contact member and carrier,means cooperative with the auxiliary contact member to establish a shuntcircuit around said blow-out coil, and a magnet coil for actuating thearmature.

5. In a magnetically operated switch, in combination, a pivotallymounted arn'iature member, a stationary contact member, a movablecontact member for engaging the stationary contact member to establish acircuit, said armature having a pivotally mounted carrier for themovable contact member, a blow-out coil for developing an arc-rupturingfield about the contact members, said blow-out coil being connected inseries circuit relation with the contact members, an auxiliary contactmember carried by and electrically connected to the movablecontactmember and carrier, means cooperative with the auxiliary contactmember and carrier to establish a shunt circuit around said blow outcoil, said auxiliary contact member being disposed to interrupt theshunt circuit before the contact members are separated. and means foractuating the armature to etl'ect the operation of the auxiliary contactmember.

6. In a switch, in combination, a movably mounted armature, a contactcarrier pivotally mounted on the armature, a movable contact membermounted on the contact carrier, a contact member disposed to receive themovable contact member, a spring disposed to bias the contact carrier ina predetermined direct-ion about its pivot point, said spring beingdisposed to cause a wiping action between the contact members when thearmature is actuated, an auxiliary contact member mounted on the contactcarrier, said auxiliary contact member being disposed to be actuatedupon the rotation of the contact carrier about its pivot point caused bythe operation of the armature, and means for actuatingthe armature.

K. In an electric switch, in comb1nat1on, a stationary contact memberand a cooperative movable contact member, an armature for actuating themovable contact member, a contact carrier pivotally mounted on one endof the armature disposed to carry the morable contact member, a biasingspring;- connected to one end of the contact carrier to retain thearmature in the open position. a blowout coil for extinguishing the arebetween tbe cont-act members, said coil being connected in seriescircuit relation with the contact members through the contact carrier, abrush prorided on the contact carrier disposed to bridge the blowoutcoil connections in response to the closure of the armature and themovement of the contact carrier about its pivot point under the controlof the biasing spring, and a coil for actuating' the armature againstthe force of the biasing spring.

In testimony whereof, I have hereunto subscribed my name this 20th dayof March, 1928.

HAROLD E. VH1! E.

